Early Impact of Bevacizumab on the 99m Tc-HYNIC-PSMA-11 Uptake in a Case of Recurrent Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is a highly vascularized tumor with reported high prostate-specific membrane antigen (PSMA) expression. On the other hand, bevacizumab as an antiangiogenesis drug is increasingly used in the treatment of GBM recurrence. We present a case of GBM recurrence with significant reduction of 99m Tc-HYNIC-PSMA-11 uptake in her tumor 1 week after administration of 2 doses of bevacizumab with 2 weeks' interval. This case emphasizes the main mechanism of PSMA uptake in GBM secondary to angiogenesis and also implies a potential interaction of bevacizumab with PSMA uptake that should be especially considered during diagnostic and therapeutic application of PSMA radiotracers in GBM.